Wednesday, February 13, 2013

What To Do When Fuel Gauge Stops Working

Fuel Gauge Behaves Erratic

Fuel Gauge Not Working.

First understand What exactly is Fuel Gauge unit:

Very important aspect of vehicle.Previously old model cars were not having these functions.Just assume you are driving and suddenly the car stops running in middle of highway and you come to know that there is no enough fuel to drive your car.You are on middle of road and there is no possibility of getting fuel because all gas stations are near to city.
So fuel gauge unit is very important.
It is acknowledged as  gas gauge or a fuel gauge. With the help of this device you come to know the level of fuel present in the fuel tank of any vehicle.

There are two parts in the fuel gauge: an signal indicator and a sense detecting unit.

The fuel gauge unit with other gauge units like speedometer, odometer,temperature gauge,heat gauge etc is situated on dashboard. This unit signifies the moderation of fuel.

When the fuel is full the signal needle goes on Full mark "F" and in the same way when fuel is empty the indicator mark goes to empty mark "E".
There is letter 'E' and letter 'F' spaced with markings on the fuel gauge unit.

You have to fill the fuel from any local gas station when the signal shows less fuel, which is near to E.

The Needle works and function by signal system.
The needle which is connected to a potentiometer in the sensing unit.
So by this process the needle moves from full to empty.

Types Of Problem Mostly Noticed:

  • Fuel gauge needle jammed underneath the pin.
  • Or is it rising and falling from full level to the empty level strangely! 
  • Or there is no movement to needle.
  • Or the fuel indicating needle is just of full level with no fuel in it.

These are basic signals specifying something certainly drastically wrong with the Fuel gauge unit and you need to repair it. 

As you already know now that fuel gauge unit works by two main parts

Fuel sensing unit and Fuel level indicator,
the sensing unit contains a smooth floating to & fro movable needle and the fuel indicating unit calculates the flow of current.

Details are shared below:
Regarding sensing unit needle ,it is connected to a electrical part called potentiometer as already said before.
Now this potentiometer operates by electronic component called resistor.
When the resistors resistance current value gets low the needle is on empty and when the resistors resistance current value gets high,the needle is on full mark.

The movement of the needle can be seen on the indicator unit,which is located on dashboard.

Now all this info is produced by minute sensor located in gas tank.This sensor is called fuel level sensor.This sensor gives details about fuel level and that is what you see on the indicator unit or fuel gauge.

There are few possible reasons to cause these problem and here we will discuss the details:

  • A faulty Fuel level sensor.
  • A problem with Needle or float assembly causing issues like needle to jump from full to empty.
  • A clogged fuel pump, in that case get the fuel filter cleaned,.
  • A faulty fuel gauge unit,if the internal circuit goes short the fuel gauge unit will not work.Yes its electronic device and it can go faulty someday.
  • A blown or shorted fuse controlling fuel unit .
  • A issue with wiring from fuel tank to the fuel gauge unit on dashboard.

Sometimes Tapping the unit with hand helps to make the unit work.Just tap it slowly few times and see if starts operating or not.

On most of such cases the problem is related to this of what is mentioned above.

On major failure cases the problem is no gauges working,on that case the complete instrument cluster board has to be replaced.

Yes there are few stores who deals with repairing instrument cluster boards.But if that's not possible then getting it replaced is the only possibility.

Hope this details help you to understand the working of fuel gauge and basic troubleshooting to make it work.


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